Based initially on the idea of a very swift 4X game, and then adding the idea of dealing differently with adjacency, Theseus is a kind of 4X game in which players control motherships "wormholing" through space in order to colonize distant planets.
On the game, players take turns using avaiable actions to open wormholes, go through them, close them, colonize planets or "uncolonize" other players' planets. Players always have, on their turn, the ammount of actions equivalent to the ammount of colonized planets they have - if they don't have any, they are exterminated.
The game "board" consists of 12 planet tiles, each with a numbered wormhole already attached to it and two other open ends. When players open a new wormhole in an open end of a planet tile, they randomly pick a numbered tile representing the planet to which the wormhole leads to, thus making the planet the player is in and the destination planet "adjacent". Whenever a player gets 8 colonies, he/she wins. And, basically, that is it, but it was hard to explain it in words here. Check it out physically, it will flow a lot easier!